Representation by women has been a significant issue in Canadian politics since 1900.

The first woman elected to a provincial legislature in Canada was Louise McKinney in the 1917 Alberta general election, while the first woman elected to the House of Commons was Agnes Macphail, in the 1921 Canadian federal election. Although female representation in politics has massively increased since then, and political parties have identified increasing the number of female candidates as an organizational and political goal, women are still underrepresented in politics compared to the general population. Canada has had one woman prime minister, Kim Campbell.

Political parties have occasionally achieved balanced representation in their elected caucuses, but mainly as a byproduct of a party collapse – for example, in the 1993 election, the Progressive Conservatives achieved gender parity in their elected caucus, but only by virtue of electing just two Members of Parliament nationwide and losing official party status. At various times, parties have also had 100 per cent female representation in their caucuses, but again only by virtue of having a caucus that consisted of just one or two members.

The Yukon New Democratic Party attained the distinction, in the 2011 Yukon general election, of becoming the first party with official party status ever to have an elected caucus that reached or exceeded parity between women and men, with four women and two men elected as MLAs. The Alberta New Democratic Party attained the distinction, in the 2015 Alberta general election, of coming the closest that a governing party caucus has ever come to attaining gender balance — the party's caucus had 25 women and 28 men, representing a caucus that was 47 per cent female."Young MLAs, many of them female, will soon rule in Alberta". Toronto Star, May 9, 2015.

The non-partisan consensus government of the Northwest Territories achieved near gender parity across the entire legislature in the 2019 Northwest Territories general election, with nine women and 10 men elected as MLAs; at the first formal meeting of the legislative assembly, the MLAs selected a woman, Caroline Cochrane, as premier, and chose women for four of the six cabinet roles.Ollie Williams, "Here's who will be in Caroline Cochrane's NWT cabinet". Cabin Radio, October 24, 2019. After one of the 10 male MLAs resigned his seat in 2021, the resulting by-election was won by a woman, making the Northwest Territories the first jurisdiction in Canadian history to have an outright majority of its legislators be women.

As of 2010, Canada ranked 50th in the world for women's participation in politics, with women holding 23 per cent of the seats in federal, provincial and territorial legislatures."Canada 50th in participation by women in politics". Toronto Star, March 8, 2010. At the federal level, Canada was tied with Mauritania for 49th place."Women in national parliaments". Inter-parliamentary Union, February 28, 2010.

Federal politics

At the federal level, women first earned the right to vote in 1917, albeit in a limited capacity: the franchise was only extended to those who were in active military service or related to a man who was. This was followed by full suffrage in 1918, and the right to stand for election to the House of Commons in 1919.

In the 1921 election, the first general election where women had full participation, five women stood as candidates: Harriet Dick, Rose Mary Henderson, Elizabeth Bethune Kiely, Agnes Macphail and Harriet Dunlop Prenter. Macphail was the only one successful in winning a seat, and she became the first woman to be elected into the House of Commons. Macphail was re-elected in the next four elections, and was the only woman in the House of Commons until the 1935 election, when she was joined by Martha Black.

In the 1940 election, Macphail was defeated and Black did not stand as a candidate, but Dorise Nielsen was elected, and Cora Taylor Casselman was elected in a 1941 Edmonton by-election to succeed her late husband. On March 13, 1944, Casselman became the first woman ever to preside over the House of Commons as acting Speaker, on an occasion when speaker James Allison Glen had to briefly step away from the chair and deputy speaker Joseph-Arthur Bradette was unavailable.

Nielsen and Casselman were both defeated in 1945, but Gladys Strum was elected that year. Strum, in turn, was defeated in 1949, the only election after 1921 in which no female candidates were elected to Parliament at all. However, Ellen Fairclough was elected to the House in a by-election the following year.

In the subsequent 1953 election, four women – Fairclough, Margaret Aitken, Sybil Bennett and Ann Shipley – were elected to Parliament. Every subsequent election has had at least two women elected to Parliament, except 1968 when Grace MacInnis was the only woman elected.

Shipley became, in 1955, the first woman in Canadian history to introduce the formal motion to accept the Speech from the Throne of the government of Louis St. Laurent.

Fairclough became, in 1957, the first woman appointed to the Cabinet of Canada by John Diefenbaker; she was also named as Acting Prime Minister for two days in 1958 while the PM was out of the country on a state visit, the first woman ever to be given that duty.

The number of women elected to the House reached double digits for the first time in the 1979 election, when 10 women were elected, and among those, Flora MacDonald. When Joe Clark became Prime Minister of Canada in 1979, MacDonald was appointed by him the first female Secretary of State for External Affairs in Canadian history, and one of the first female foreign ministers anywhere in the world.

In 1980, Jeanne Sauvé was appointed the first female speaker of the House of Commons in the 32nd Canadian Parliament. In 1984, her leader, Prime Minister Pierre Elliot Trudeau advised Queen Elizabeth II to make her the Governor General of Canada, which title she assumed (after resigning her seat in Parliament) on 28 January 1984. Sauvé would continue as vicereine until Christmas 1989.

In 1993, Kim Campbell became the first woman to be appointed Prime Minister of Canada when she was passed the torch by Brian Mulroney. She lost the subsequent general election.

Federally, the 2021 election holds the record for the most female candidates in a single election, with 582 women running for office that year. In terms of women elected to the House of Commons, the 2021 election also holds the record, with 103 successful female candidates.

Of the major federal political parties, the New Democratic Party has nominated the most female candidates in every election since its creation, except in the 1962 election, when it tied with the Progressive Conservatives, and the 2008 election, when the Liberals nominated the most female candidates for the first time in their history. The Marxist-Leninist Party of Canada nominated more women than the New Democrats in 1979 and 1980, although they are a minor party who have never won a seat in the House of Commons. Between the 1935 and 1958 elections, the top ranking was consistently held by either the Co-operative Commonwealth Federation or the Labor-Progressive Party.

Leadership

Kathryn Cholette of the Green Party was the first woman ever to win the leadership of a federal political party, and Audrey McLaughlin of the New Democratic Party was the first woman to win the leadership of a party with seats in the House of Commons.

Canada has had one woman prime minister, Kim Campbell. She became prime minister before the 1993 federal election by winning the leadership of the governing Progressive Conservatives, but lost the subsequent general election. No woman has yet been elected Prime Minister of Canada in a general election.

Three women — Sheila Copps, Anne McLellan, and Chrystia Freeland — have served as deputy prime minister.

Several women, including Mary Walker-Sawka, Rosemary Brown and Flora MacDonald, have run for the leadership of federal political parties. Brown was the first black woman to ever run for leadership of a federal political party. MacDonald unwittingly lent her name to a political phenomenon known as "Flora Syndrome" when some of her own committed delegates at the 1976 Progressive Conservative leadership election decided not to vote for her, a loss of support which some commentators attributed to sexism.

Four women — Deborah Grey, Nycole Turmel, Rona Ambrose and Candice Bergen — have served as Leader of the Official Opposition. All of the women served as interim leaders of their parties during leadership campaigns; however, Grey was an acting Leader of the Official Opposition.

Four other women have served as leaders of political parties in the House of Commons: Alexa McDonough, who succeeded McLaughlin as leader of the New Democratic Party in 1995; Elsie Wayne, who served as interim leader of the Progressive Conservatives in 1998; Elizabeth May, who entered the House of Commons in the 2011 election as the leader and first elected MP of the Green Party; and Candice Bergen, who served as interim leader of the Conservative Party of Canada following the resignation of Erin O'Toole.

Two smaller political parties which, do not hold any seats in the House of Commons are also led by women: Communist Party of Canada (Marxist-Leninist) – Anna Di Carlo Animal Alliance Environment Voters Party of Canada – Liz White

This dearth of women in political leadership may, in some ways, be attributable to women's general exclusion from important cabinet positions that are seen as stepping stones to leadership. Women were largely excluded from Canadian cabinets until the 1970s. Only in rare instances do women comprise a significant proportion of Canadian cabinets, as in the case of then-Ontario Premier Bob Rae's first cabinet in 1990, in which 11 of 26 ministers were women. As of July 2013, the Harper Cabinet had 11 female ministers in a cabinet of 39, though most held minor portfolios; in October 2015, Justin Trudeau became the first prime minister to appoint a fully gender-balanced cabinet with equal numbers of both men and women.

Senate

Although women gained the right to stand for election to the House of Commons in 1918, women did not have the right to be appointed to the Senate of Canada until 1929, when Edwards v Canada (AG) (commonly known as the Persons Case) was decided. The following year, Cairine Wilson was appointed as the first woman to sit in the Senate. In 1955, Wilson achieved another first, becoming the first woman to become Deputy Speaker of the Senate.

The first female Speaker of the Senate was Muriel McQueen Fergusson, who served in the role from 1972 to 1974.

In 1993, Joyce Fairbairn became the first female senator to be named Leader of the Government in the Senate. She held the role until 1997. Two more women have since had the role: Sharon Carstairs (2001–2003) and Marjory LeBreton (2006–2013).

The Famous Five, a group of five women whose activism originally secured the right of women to be named to the Senate, were posthumously named as honorary senators in 2009. The women – Emily Murphy, Henrietta Muir Edwards, Nellie McClung, Irene Parlby and Louise McKinney – are the only people in the history of the Senate to be given this honor.

In November 2020, the Senate briefly reached gender parity, with 47 male and 47 female members.

Provincial and territorial politics